Question 1

Calcium concentration in the blood is regulated by which of the following hormones?&#10;A) Calcitriol&#10;B) Parathyroid hormone&#10;C) Cortisol&#10;D) Both a and b

Accepted Answer

Calcium concentration in the blood is regulated by both calcitriol and parathyroid hormone. Calcitriol is responsible for promoting calcium absorption from the small intestine while parathyroid hormone is responsible for increasing calcium released from bones and decreasing calcium excretion in the urine. Cortisol, on the other hand, has some effects on calcium metabolism but is not primarily responsible for its regulation.

Question 2

Which of the following protein hormones produces a decrease in blood glucose by causing glucose to enter cells for energy production?&#10;A) Insulin&#10;B) Aldosterone&#10;C) Thyroid hormone&#10;D) Cortisol

Accepted Answer

Insulin is produced by the pancreas and its primary function is to regulate blood glucose levels. It causes cells to take up glucose from the blood for energy production or storage, thus decreasing blood glucose levels. Aldosterone is produced by the adrenal glands and regulates sodium and water balance in the body. Thyroid hormone is produced by the thyroid gland and regulates metabolism. Cortisol is produced by the adrenal glands and is involved in stress response and regulating metabolism, but it does not directly affect blood glucose levels in the same way that insulin does.

Question 3

An example of a polypeptide hormone that is part of the complex integrative function of many hormones involved in development of the human organism is:&#10;A) growth hormone.&#10;B) estrogen.&#10;C) cortisol.&#10;D) thyroxine.

Accepted Answer

Growth hormone is a polypeptide hormone that is involved in the complex integrative function of many hormones involved in the development of the human organism, particularly in regulating growth and metabolism. It is released by the pituitary gland and stimulates the production of insulin-like growth factor-1 (IGF-1) in the liver and other tissues, which in turn promotes bone and tissue growth.

Question 4

Which one of the following hormones requires a transport protein to move it through the circulation?&#10;A) Prolactin&#10;B) Aldosterone&#10;C) Estrogen&#10;D) Parathyroid hormone

Accepted Answer

Estrogen is a steroid hormone and, like all steroid hormones, requires a transport protein, such as sex hormone-binding globulin (SHBG), to move through the circulation. Prolactin, aldosterone, and parathyroid hormone are not steroid hormones and do not require transport proteins.

Question 5

The release of thyroid-stimulating hormone (from the pituitary gland)stimulates the release of thyroid hormones from the thyroid gland.When the level of thyroid hormones increases in the circulation,they shut off the release of TSH from the pituitary.This is an example of which type of feedback?

A) Open loop feedback
B) Positive feedback
C) Negative feedback
D) None of the above

Accepted Answer

This is an example of negative feedback, where the response of the system (decrease in TSH release) opposes the initial stimulus (increase in thyroid hormone levels) to maintain homeostasis.

Question 6

Considering the classification of hormones by structure,an example of a steroid hormone would be:&#10;A) testosterone.&#10;B) parathyroid hormone (PTH).&#10;C) cortisol.&#10;D) all of the above.

Accepted Answer

The answer of Considering the classification of hormones by structure,an...

Question 7

The half-life of a protein hormone in plasma is:&#10;A) long,usually greater than 90 minutes.&#10;B) long,at least 24 hours.&#10;C) short,more than 1 hour but less than 3 hours.&#10;D) short,approximately 10 to 30 minutes.

Accepted Answer

The best choice is D as a short half-life indicates that the hormone is rapidly degraded and cleared from the plasma, which is typically around 10 to 30 minutes for protein hormones. Choices A and B are incorrect as they both suggest long half-lives, which are rare for protein hormones. Choice C is closer to the correct answer than A and B, but it still suggests a longer half-life than what is typically observed in protein hormones.

Question 8

A group of hormones produced by the gastrointestinal tract that stimulates insulin secretion from the pancreas and slows the rate of gastric emptying is referred to as:&#10;A) incretins.&#10;B) insulinomas.&#10;C) calcitriols.&#10;D) steroids.

Accepted Answer

The group of hormones produced by the gastrointestinal tract that stimulate insulin secretion from the pancreas and slow the rate of gastric emptying are called incretins. Examples of incretins include glucagon-like peptide-1 (GLP-1) and gastric inhibitory peptide (GIP). Insulinomas are tumors of the pancreas that produce excessive amounts of insulin. Calcitriols are a form of vitamin D implicated in the regulation of calcium and phosphate metabolism. Steroids are a class of hormones that are not typically involved in the regulation of insulin secretion or gastric emptying.

Question 9

Which one of the following statements concerning protein hormones is correct?&#10;A) A protein hormone binds to a receptor within the cell or on the nucleus of the cell,thereby directly affecting protein synthesis.&#10;B) A protein hormone,once bound to its receptor,activates adenylyl cyclase,which leads to eventual phosphorylation of other cellular enzymes.&#10;C) The complex of protein hormone/receptor diffuses into the cell nucleus and has a suppressing effect on RNA synthesis.&#10;D) All protein hormones are bound to a transport protein to move through the circulation.

Accepted Answer

Protein hormones usually bind to cell surface receptors and activate signal transduction pathways inside the target cell. One common pathway involves activation of adenylyl cyclase, which leads to the production of cyclic AMP (cAMP) and subsequent activation of protein kinase A (PKA). PKA can then phosphorylate various cellular enzymes, leading to changes in cell metabolism and gene expression. This is a general mechanism for many protein hormones, including epinephrine, glucagon, and follicle-stimulating hormone (FSH). Option A is incorrect because protein hormones usually do not enter the cell or nucleus, but instead act through membrane-bound receptors. Option C is also incorrect, as protein hormones usually have a stimulatory effect on gene expression rather than suppressive. Option D is partially correct in that some protein hormones may bind to transport proteins like albumin in the circulation, but not all protein hormones require this mechanism for transport.

Question 10

An example of a protein hormone synthesized in the hypothalamus,with the principal action to control the release of thyroid-stimulating hormone,is:&#10;A) prolactin.&#10;B) thyroid stimulating hormone.&#10;C) ACTH.&#10;D) thyrotropin releasing hormone.

Accepted Answer

The protein hormone synthesized in the hypothalamus that controls the release of thyroid-stimulating hormone is thyrotropin-releasing hormone (TRH). Therefore, the best choice is D, thyrotropin-releasing hormone. Prolactin, thyroid-stimulating hormone, and adrenocorticotropic hormone do not control the release of thyroid-stimulating hormone.

Question 11

Which one of the following statements concerning steroid hormones is correct?&#10;A) Steroid hormones attach to a receptor on the surface of a cell,which eventually induces enzyme phosphorylation within the cell.&#10;B) Steroid hormones are hydrophobic when free and bind to intracellular receptors in the nucleus.&#10;C) Steroid hormones,because of their structure,are not bound to carrier proteins as they circulate in the blood.&#10;D) Steroid hormones have a very short half-life (usually <30 minutes)in the circulation.

Accepted Answer

The answer of Which one of the following statements concerning...

Question 12

The analytical method that provides better analytical sensitivity in hormone detection than other methods such as immunoassay or receptor-based assays is:&#10;A) tandem mass spectrometry.&#10;B) bioassay.&#10;C) immunometric assay.&#10;D) spectrophotometry.

Accepted Answer

The answer of The analytical method that provides better analytical...

Question 13

As part of homeostatic control by hormones,the metabolism of electrolytes and water balance is controlled in part by the renal system.What hormone synthesized by the kidneys affects water and electrolyte balance?

A) Aldosterone
B) Renin
C) Vasopressin; antidiuretic hormone (ADH)
D) Insulin

Accepted Answer

The answer of As part of homeostatic control by hormones,the...

Question 14

Binding to a receptor at the outer cell membrane to induce phosphorylation via adenylyl cyclase and cAMP of certain intracellular enzymes is a property of which class of hormone?&#10;A) Protein&#10;B) Steroid&#10;C) Amino acid-derived&#10;D) Both a and c

Accepted Answer

The answer of Binding to a receptor at the outer...

Question 15

Which of the following is an effect of increased parathyroid hormone (PTH)secretion from the parathyroid gland in the homeostatic control of serum calcium?&#10;A) Decreased blood calcium levels&#10;B) Increased renal absorption of phosphate&#10;C) Decreased bone calcium efflux from the skeleton&#10;D) Increased intestinal absorption of calcium

Accepted Answer

The answer of Which of the following is an effect...

Deck 25: Hormones